Planning control enclosure cache memory

The control enclosure uses memory features to control the initial amount of memory and subsequent memory upgrades.

Each of the six memory channels in each CPU has two DIMM slots. A total of 12 DIMM slots per CPU and 24 DIMM slots are available per node canister and 48 DIMM slots are available per enclosure. You can install distinct memory configurations in those 24 DIMM slots in each node canister. (Each canister must have the same amount of memory and the same configuration.)

Memory configurations for each FlashSystem 7200 control enclosure

The following table shows the available memory configuration for each FlashSystem 7200 control enclosure. Each column gives the valid configuration for each total enclosure memory size. DIMM slots are listed in the same order that they appear in the node canister. Both node canisters must be configured identically to create the total enclosure memory size.

To ensure proper cooling and a steady flow of air from the fan modules in each node canister, blank DIMMs must be inserted in any slot that does not contain a memory module.
Table 1. Available memory configurations for a FlashSystem 7200 control enclosure
DIMM slot Memory configuration options
256 GB 768 GB 1,536 GB
F0 Blank 32 GB 32 GB
F1 Blank Blank 32 GB
E0 Blank 32 GB 32 GB
E1 Blank Blank 32 GB
D0 32 GB 32 GB 32 GB
D1 Blank Blank 32 GB
CPU 0
A1 Blank Blank 32 GB
A0 32 GB 32 GB 32 GB
B1 Blank Blank 32 GB
B0 Blank 32 GB 32 GB
C1 Blank Blank 32 GB
C0 Blank 32 GB 32 GB
 
C0 Blank 32 GB 32 GB
C1 Blank Blank 32 GB
B0 Blank 32 GB 32 GB
B1 Blank Blank 32 GB
A0 32 GB 32 GB 32 GB
A1 Blank Blank 32 GB
CPU 1
D1 Blank Blank 32 GB
D0 32 GB 32 GB 32 GB
E1 Blank Blank 32 GB
E0 Blank 32 GB 32 GB
F1 Blank Blank 32 GB
F0 Blank 32 GB 32 GB
 
Memory per CPU 64 GB 192 GB 384 GB
Memory per node canister 128 GB 384 GB 768 GB
Total memory per control enclosure 256 GB 768 GB 1,536 GB

Node canister orientation for DIMMs

Figure 1 shows the location of the CPUs and the DIMM slots within a node canister. The node canister chassis is oriented with the three PCIe networking adapters in card risers to the right (rear). Three fan modules to the left sit atop the NVMe-attached FlashCore Modules or other Flash drives at the front of the node canister. This is the proper orientation for the node canister because the DIMM labels are easily read. DIMM slots A0 and D0 are shown for each CPU.
Figure 1. Location of CPUs and DIMM slots within the node canister
Location of CPUs and DIMM slots

Closeup view of DIMM slot labels

White labels on the printed circuit board identify the DIMM slots. For example, Figure 2 shows slots C0, C1, and B0.
Figure 2. DIMM slot labels printed in white on the circuit board of the node canister
Close up view of DIMM slot labels